This invention relates to a refill eraser used for erasing letters, figures, etc., from a sheet of paper on which they are written.
Heretofore, erasers having various configurations are known. Among them, those commonly used have a flat parallelepiped configuration. A typical eraser used for technical drawing has a wooden shaft similar to that of a pencil, and a sand-contained eraser core which is bigger than a core of a pencil inserted or filled into the shaft over its entire length.
As discussed in Japanese Utility Model Publication No. Sho 51-32492, there is also known a refill pencil which comprises refill members each including a holding barrel and a pencil core whose rear end is fitted into a front end of the holding barrel having a smaller diameter, the refill members being longitudinally filled into and held within an elongated tubular shaft in engagement relation to each other.
In the commonly used flat parallelepiped erasers mentioned above, the letters, etc. written on a sheet of paper are erased therefrom, at an early stage of use, by rubbing the written surface with its four corner portions and four side portions (thus, with eight spots in total). However, since that portion of the eraser which contacts the paper surface is small in area, erasing efficiency is not good when the letters, etc., which are written in a large area, are to be erased. After an extended period of use, the corner portions are worn and therefore the contacting area relative to the paper surface becomes overly large. The result is that when letters, etc., which are written in a small area, are to be erased, there is a possibility that letters adjacent to the letters which are to be erased (that is, those letters which are not desired to be erased), are inadvertently erased.
With respect to the refill eraser having a wooden shaft and an eraser core filled therein, it has such a shortcoming that it is difficult to be used for other purposes than a special purpose for erasing a part of a device having a small size or the like. Moreover, since it is necessary to sharpen the wooden shaft, a troublesome work is required.